Car enthusiast typically try to protect their automotive investments, particularly when the investment is a high-end or high-performance sports car. A turbo charged engine requires more maintenance and vigilance than most other engines. With a turbo charged motor, one must frequently check the oil levels. Automotive dealers typically recommend an oil check at every gasoline fill up. This is due to the fact that turbo charged engines experience more “blow by” than normally aspirated cars, and can consume quite a bit more oil. Even if the motor is otherwise healthy, it is not uncommon to burn between a half to a full quart of oil between oil change intervals. Running this low on oil at the wrong time could result in catastrophic engine failure.
A common engine oil dipstick consists of a long small diameter tube (˜0.5″) that sits perpendicular to the oil pan, and rises from inside the oil pan upwards toward the top of the motor, usually terminating at a convenient easy to reach spot. The dipstick itself, normally nothing more than a long piece of spring steel with a handle sits inside this tube, allows a portion of the stick to make contact with the oil in the oil pan. The stick length is designed so that the oil level in the pan can be determined by seeing where oil is deposited on the stick. Dipsticks usually have some kind of graduated markings on them that correlate to high or low readings.
Many modern automobiles utilize a sealed dipstick handle configuration. A sealed dipstick handle typically has a grove on the outside diameter and an o-ring that sits in the groove. When the dip stick is inserted into the tube, and the handle is seated in its normal position, the o-ring seals off the dipstick tube from the outside environment, effectively keeping anything from getting in or out of the dipstick tube that leads to the oil pan.
The problem with previous sealed systems is that when the dipstick is pulled out of its tube (to check the oil level) the o-ring and handle material form a piston of sorts, and this piston pulls a vacuum up thru the tube. Minute as this force is, it is enough to skew the dipsticks readings by a wide margin, even as much as twenty percent. This can be verified by wiping the dipstick clean and reinserting and rechecking the results. Consequently, it can be difficult to read where exactly the oil level is on the dipstick. Additionally, one side of the dipstick will have a higher mark than the other. Another problem is that the readings are very inconsistent.
One previous cure for such problems is to remove the o-ring from the dipstick handle prior to checking the oil. When the dipstick is re-inserted without the o-ring, air is able to pass around the body of the handle into the tube, and the measurements are more consistent. Once the measurement is complete, the o-ring must be reinstalled on the dipstick to avoid oil contamination. Although this process works, it is time consuming and usually results in damaged o-rings. For example, repeated removal and replacement of o-rings can tear them, or otherwise damage them.